There are cases where a medical component to be implanted in a living body is formed of a ceramic material. A zirconia sintered body for use as a medical material is known as such a ceramic material (see Patent Document 1, for example). The zirconia sintered body for use as a medical material described in Patent Document 1 contains tetragonal zirconia stabilized by Y2O3 as a main component. Moreover, this zirconia sintered body for use as a medical material has a configuration containing 0.05 to 0.5 parts by weight of both SiO2 and TiO2. With this configuration, the zirconia sintered body for use as a medical material is white, and is suppressed from changing its color from white when being sterilized by the irradiation of gamma-rays.
Also, a blackened zirconia ceramic for implantation in a living body is known as a medical ceramic material (see Patent Document 2, for example). Patent Document 2 discloses a configuration in which a deoxidation ratio of a material for this blackened zirconia ceramic is greater than 10 ppm. With this configuration, blackening of the blackened zirconia ceramic is realized. Moreover, since the deoxidation ratio is greater than 10 ppm, the color tone of the blackened zirconia ceramic is not substantially changed between before and after sterilization by the irradiation of gamma-rays.